1. Field of the Invention
This invention relates to an antenna module, more particularly to an antenna module for a portable electronic apparatus.
2. Description of the Related Art
Presently, a conventional antenna module for a portable electronic apparatus is grounded through a dielectric substrate of the portable electronic apparatus. In view of the current trend in the design of the portable electronic apparatus to be shorter, smaller, lighter and thinner, the decreased length of the dielectric substrate in the portable electronic apparatus has an adverse effect on a radiation gain of the conventional antenna module. For example, referring to FIG. 1, gain values (indicated by rhombic blocks in FIG. 1) of a conventional antenna module having a substrate with a length within a range from 60 mm to 130 mm at an operating frequency of 1850 MHz are shown, wherein the conventional antenna module having the substrate with the length of 90 mm has a radiation gain of −0.4 dBi.